Jlrose24

I'm new at all this stuff but I'm really interested. I have a 94 4x4 with a sr5 engine. It has a ton of miles on it 336000. I feel like since it the v6 I should be able to pull up hills without loosing power but I do. I've been told to do a compression check but I'm not sure how to. Anyways you guys seem to have some great advice so advise away I need all the help I can get

RJR

How big a hill? The 3vz has more power than a 22re, but not that much more. It's still underpowered by modern day standards for a 4000 lb vehicle, and will definitely slow down on any hill over about 4% slope. At 336,000 miles, it could be losing some zip as well, depending on how well it's been maintained.

Do a search for "compression check" and you'll find plenty of howto info. Use Google and add "f116" to the search string to narrow it down to this forum.

Also check timing - that has a lot to do with power. Running mid-grade gasoline instead of the lowest grade will also help, assuming everything else is up to snuff.

scope103

"Eric the Car Guy" is better than most; here's his on compression check:
DO check timing; the timing light will cost you about $20 http://www.harborfreight.com/xenon-t...ight-3343.html. For some reason, lots of folks are more willing to spend a few hundred on replacement parts at random. Timing CAN cause loss of power and it is relatively easy to fix.

RJR

Also, in terms of climbing hills, a healthy 3vz (and a 22re, for that matter) will run at 4000 rpm all day and love it, and will put out about 30% more power than at 3000 rpm. Don't be afraid to downshift and wind it up when the road gets steep and you start bogging down on the hills.

Jlrose24

The hills I'm talking about are rather small and when I shift down and rev it up it still has trouble maintaining speed. The guy I bought it from just told me there is an o2 than he ripped out and never replaced could that be contributing to the problem?

thefishguy77

iTrader: (1)

That could be messing with the computer. Make sure the connections are still there and replace the O2 sensors. But at that millage a compression check and leak down test should be a priority. If the motor does have compression issues O2 sensors will make no difference. Good luck hope this helps.

RJR

The O2 sensor will affect operation at part throttle, but is not normally involved at full throttle. At that point the ECU is just operating from its internal map and input from the other various sensors to set ignition timing and injector duration.

Is the check engine light on? (Does it even work when you first turn the key?) Have you checked for diagnostic codes? (Takes a paper clip). A code 52 (no signal from knock sensor) will cause retarded timing and low power. With the O2 sensor missing you should definitely be seeing a check engine light code.

Pull the diagnostic codes, follow up on the ignition timing and compression tests, and let us know what you find, and we'll go from there.

Jlrose24

Thanks for all the info I'll try something's when the weather clears as I do not have a garage to work in. I'll let you know what happens when it happens

RJR

I edited this to be more clear as to the pause lengths that separate digits, codes, and the whole repeating string.

If you haven't checked the codes on a 94 4runner before, here's the basic steps.
- Find the "Diagnostics" connector under the hood. Should have a cover on it labeled "Diagnostics", next to the fuse box on the passenger side of the engine.
- Open the cover, look at the terminal map inside, and short TE1 to E1. A paper clip or short end of wire works well.
- Turn the key to "ON", but do not start the engine.
- The check engine light should be flashing
- Steady flashing means no stored codes
- If there are codes, the light will flash in bursts. Count the flashes to get the code. Digits are separated by short pauses, codes are separated by longer pauses.
-- 1.5sec pause separates digits, 2.5sec pause separates codes, 4.5 sec pause separates when the whole pattern repeats.
For example, a code 32 will be 3 pulses - 1.5sec pause - 2 pulses - 4.5sec pause, repeat.
If there are multiple codes, they will come out in sequence. Example: codes 32 and 57 will be 3 pulses-1.5sec pause-2 pulses-2.5sec pause-5 pulses-1.5sec pause-7 pulses-4.5sec pause, entire pattern repeats.
The flashing will continue until you turn off the key and remove the jumper.

Once you have the codes, you can look them up on line to see what they mean, or ask here.

Some of the stored codes might be old, so it may be a good idea, once you've written them down, to pull the EFI fuse in the fuse box next to the diag connector for 30 seconds to reset all of the codes. Then drive it for a couple of days and see which ones come back. That will tell you which ones are causing issues right now.

Badger62811

First time seeing this process explained. In great detail too. I haven't ever had CEL come on so I feel like kind of a noob.

Thank you. I'm putting this in my toolbox.

Jlrose24

Yes my cel is on and I didn't know that trick at all. Thanks for the tip